Flotation concentration



Patented Sept. 17, 1929 UNITED STATES PATENT OFFICE SHERWIN P. LOWE, OF DENVER, COLORADOjASSIGNOR TO R. H. CHANNING, AGENT,

OF DENVER, COLORADO FLOTATION CONCENTRATION No Drawing.

My invention relates tothe concentration of mineral values in ores by oil flotation and has particularly in View the separation of an ore containing sulphides: of copper, zinc and iron into a copper concentrate, a zinc concentrate and a tailing carrying most of the iron. In the concentration of ores of this type, it is well known that the separation is materially assisted by having the pulp in an alkaline condition due to the presence of lime which is added in preparing ore for flotation. I My improvement consists in the discovery that a much better separation can be made if a careful control is maintained of the alkalinity of the pulp, due to the amount of lime,

at different stages of the process.

For instance, while the copper concentrate isbeing removed the pulp should be just alkaline, but after removing the copper concentrate it is easier to obtain high grade zinc concentrate and a good extraction of zinc by increasing the alkalinity. If the zinc concentrates thus produced are to be retreated a still further increase of alkalinity before retreatment, aids materially in obtaining the best results.

The following examples will show the eifect of various conditions when treating sulphide ore assaying as follows:

Cu 1.89%, Zn 4.6%, Fe 34% Cu Zn %'Fe the concentrates assayed 12.0 4.5 29.0 the talllngs assayed .2 34.8

5 When the alkalinity of the pulp in the copper flotation cells was ..20 lbs. CaO per ton of water Cu Zn Fe the Concentrates assayed 10.5 11.0 28.0 the tallings assayed .25 4.1 35.0

9 The tailings from the above tests were then Serial No. 264,963.

Cu 711 Fe the concentrates assayed .4 %80 the tailings assayed .2 .9 34.0

When the alkalinity of the pulp in the zinc rougher flotation cells was 6 lbs. CaO per ton of water Cu Zn the concentrates assayed the tailings assayed When the alkalinit of the pulp in the zinc rougher flotation cel s was over .7 lbs. CaO i. e. 1.0 lbs. CaO per ton of water Cu Zn Fe the Concentrates assayed .7 22.0 24.0 the tailings assayed .2 .6 35.0

The concentrates from the zinc rougher flotation cells, when the pulp contained .6 lbs. CaO per ton of water was refloated, with the addition of enough lime to bring the alkalinity to .8 lbs. CaO per ton of water with the result, that the final concentrates assayed The concentrates from the zinc rougher flotation cells when the pulp contained either .3 lbs. or 1.0 lbs. CaO per ton of water, could not be retreated to produce higher than a 42% zinc concentrate.

What I claim, is:

1. A method of separating by flotation, ore containing copper, zinc and iron sulphides into a copper concentrate, a zinc concentrate and a tailing carrying a large percentage of the iron sul hides, in which the pulp during the copper otation is maintained at an alkalinity of from substantially .01 lbs. CaO to .15 lbs. CaO per tone of water and during the zinc flotation the pulp is maintained at an alkalinity of from substantially .4 lbs. CaO to .7 lbs. CaO per ton of water.

2. A method of separating by flotation, ore containing copper, zinc and iron sulphides into a copper concentrate, a zinc'conccntrate and a tailing carrying a large percentage of iron sulphides in which the pulp during the copper flotation is maintained at an alkalinity of from .01 lbs. @210 to .15 lbs. C210 per tonof water and during the zinc flotation the pulp is maintained at an alkalinity of from .4 lbs. CaO to .7 lbs. CaO per ton of Water, 5 and during the retreatment of the zinc concentrates the pulp is maintained at an alkalinity of from .8 to 1.10 lbs. (3210 per ton of Water.

In testimony whereof, I afix my signature.

SHERWIN P. LOWE. 

